A FinFET is a type of multi-gate Metal Oxide Semiconductor Field Effect Transistor (MOSFET). A multi-gate transistor incorporates more than one gate into one single device. In FinFET, a thin silicon film wrapped over the conducting channel forms the body. The name has been derived from the fact that the structure, when viewed, looks like a set of fins. The thickness of the device determines the channel length of the device. The channel length of a MOSFET is the distance between the source and drain junctions. Since the fabrication of MOSFET, the channel length of the device has been shrinking constantly so as to fabricate compact and fast devices.
The main aim of the MOSFET is to control the flow of voltage and current between the source and drain terminals. A high quality capacitor is formed by the gate terminal. The gate is composed of the silicon oxide layer, the p-body silicon and gate metallization and the p-body silicon. This capacitor is the most vital part. The semiconductor surface at the below oxide layer is located between the source and drain terminal. This is inverted from p-type to n-type by applying a positive or negative gate voltage, respectively.
In current usage, the term FinFET refers to any fin-based, multigate transistor architecture. For example, FinFET may include double-gate development efforts.